Key and lever guard for fire-alarm boxes



Dec. 10, 1929. M. J. GRACE 1,738,531

KEY AND LEVER GUARD FOR FIRE ALARM BOXES Original Filed June 30. 1924 6 a $5 L if J Z FUR FIRE BREAK GLASS PULL LEVER gwuzni oz;

Fatented Dec. it), 1929 ii at;

as that MICHAEL J. GRACE, OF CHARLESTON, SOUTH CAROLINA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TU THE GAMEWELL CUMPANY OF SETTS, A CORPORATION OF MASSACHUSETTS KEY AND Lnvnn GUARD FOB. FIR-EALABM :Boxns Application filed June 30, 1924. S rial The present invention is a guard for keys or pull levers of fire alarm signal boxes. This invention is an improvement over the well known Cole key guard shown and described in United States Patent No. 824,411, wherein a transparent plate is mounted in a spring operated door, the door being arranged before the key or alarm pull lever- In this type of device it is necessary to first break the glass or frangible element which releases the spring door and permits the same to swing open giving ready access to the key or pull lever. This type of device is objectionable because it is found that in a number of in stances the person sending the alarm breaks the glass with his hand and the shattered glass cuts or otherwise injures the hand of the person. Furthermore it is necessary with devices of the type of the Cole device to replace the glass atter each alarm.

It is also well known that it has been 'proposed to have a non-frangible, transparent element covering the key or pull lever. But in these cases the door supporting said element must i be manually and deliberately opened before access is gained to the pull lever or the key. In this instance the well established practice of breaking the glass' togain access to the key or pull lever, with which practice all persons are fully fam liar,

has been departed fromwhich may cause confusion in the sending of the alarm, resulting in no alarm being sent in,by-reason of the fact that thedoor of the guard having been deliberately pulled or otherwise opened a person may assume that the alarm has been sent in and neglect to turn the key or pull the alarm lever.

The present invention has for its object to overcome all of the above stated drawbacks and to provide further an economical and etficient key or lever guard adhering to the well kn wn practice and instructions which have long appeared on. all alarm boxes, to first break the glass and to turn key or pull lever.

The invention further has tor'its object the elimination of the usual key lock for maintaining the guard door closed and the n-ovision of a door which will snap into place n5. 'liich will be-rea dily trig JEi. open upon No. 723,418. Renewed March 30, 1929.

NEWTON UPPER FALLS, MASSACHU- the striking of the door or glass withthe knuckles or other instruments without breaking the glass. The glass is made sufliciently thick or otherwise constructed to withstand an ordinary blow from the hand without breaking it. .However it may be broken, if found necessary, with a suitable instrument thereby under any condition assuring access to the key or lever.

The invention further residesin the sundry details of construction, combination and arrangement of parts which are shown in the accom anying drawings and described in thisspecification. I

In this specification and the annexed drawings, the inventionis disclosed in the form in whiehit is considered to be the best, but

the'invention is not limited to such form because it is capable of being embodied inother I forms; and it' is to be understood that in and by the claims following the description herei in it is intended to cover the invention in whatever form it may embody withinthe scope'thereof. A 5

In the drawings in which theperferred embodiment of the invention is shown, as at present devised;

Figure 1 is a front view of a signal box provided with a key or lever guard attachment constructed in accordance with the invention; Y F

. Fig. 2 is a vertical sectional view taken substantially on line 22 ofFig. 1; Fig. 3 is a modified 'iorniot the trip lever; and r V T Fig. 4 is a modified structure embodying lock V and the fundamental features and principles of" the invention. 1

Referring particularly to thedetails of the drawings, 1 indicates the shell or housing of the usual fire alarm box which may be provided withv a movable front face or door 2, in which there is a slot through which asuitable pull lever is extendedto be accessible for sending the alarm or in which may be provided a key'lock accessible to the sender of the alarm in a manner which is well un derstood in the art. This pull lever 3 or key, as the case may be, is enclosed by theusual uard housing 46 equipped with spring actuated hinged door 5 of substantially the same structure now commonly in use. It may be found desirable however, to. eliminate the projecting guard housing 4 and to provide a suitable depression or recess in the door 2 of the box. However such depression or recess will be equipped with the spring actuated door 5, preferably of the swinging type hinged at its lower edge as at 6 and being moved to open position in any suitable manner by a spring or other means 7.

The present invention deals more particu larly with a means for maintaining the door in its normal closed position, shown inl igs. l, 2, andi, but which will be actuatedivien pressure is exerted on theTdoor or angible panel'8 torelease the door from its normally closed latched position and to permit the spring means 7 to open the door as soon as the pressure of the blow has been released.

As previously stated it is the purpose of this invention for the sender of the alarm to practice thetime-honored method familiar to al persons by first breaking the glass on the door 5. But since it is the practice of most people to attempt to break the, glass with their hand, it-is the aimof this invention. for the door to be released when the glass of the door is struck by a blow from the hand but without actually breaking the glass. To this end' the glass is made of greater thickness than usual or of such construction as to withstand an ordinary-blow from the hand without breaking, but which may be broken, 1' f found necessary, with a suitable instrument thereby under allconditions assuring access to the or lever.

One means for latching the door 5 in its normally closed position is shown in 1,

2, and 3 and consists of a lever 9, substantially of the bellcrank type pivotally mounted at its angular port-ion in a bracket or projcc tion 10 extending laterally from the inner face of the door 5 at or adjacent the distal in edge thereof, or at anyother suitable por tion which may be found more convenient and desirable on the door 5. The lever 9 is so 7 designed and constructed as to have the ex tremity A of one arm thereof to engage against the usual glass panel 8, in the manner clearly shown in Pi s. 1 and 2, and the .end B of the other arm thereof designec. to

act as a detent to engage with and abutedge of the door opening in the housing 4;, as clearly shown in Fig. 2.

The frangible panel 8 is, preferably, fitted in rabbets in the door 5 and is normally held tightly in the rabbetsby the extension I) of the spring 7. The manner of mounting the panel 8 may be varied in any suitable or deired way. WlllCll' will permit. the panel to move, under pressure, inwardly relative to the door 5, as indicated in dotted lines, Fig. 2. The latch lever 9 is normally urged to its full line position. shown in Fig. 2 by alight spring found desirable in some instances to substitute a counter-balance on the lever fgr the spring 11. The door actuating means Z" be any suitable means, but for the purpose of the present showing consists of a flat spring having one end secured to the frame of the door 5, as in F, and one end E under tension engaging against the inner wall of the bottom of the guard housing 4. 7

From the above it will be seen that when a person is about to turn in an alarm, in the event of fire, he will proceed as is usual to give the frangible panel 8 a blow,in an attempt to break the panel and gain access to alarm pull-lever or key. If this blow is delivered by the hand, thepanel will be sufiiciently strong to resist breaking, but will move inwardly, as indicated in dotted llIlBS,

Fi 2 under the blow movin the end A. of

1 b 1 7 v i 7 u 1 u I I the lever 9inwardly with 1t, which in turn causes the end B of the lever to move out of the path of the keeper edge 12 of theguard box; and since the spring 7 is constantly exerting its pressureon theframe of the guard box door 5, the door will'be moved slightly lines F 2, to clear the end B of the'latch le er9 from the keeper 12, andas soonas the pressure from. the blow is relieved from the panel 8, the spring 7; will completelts swing-f ing movement of the. door, and move it tothe full open position, shown in dotted lines of Fig. '2. This operation renders ready access to the usual alarm pull lever or to the lockkey of the door2 of the alarm box, according to the type of box upon which the invention is installed. The panel 8 will be immediately returned to its position in the rabbet,

as soon as the pressure of the blow is relieved therefrom, by the spring 11, by reason of the.

replace the frangible panel 8, because the same is not broken, and the hand of the sender of the alarm is in no way injured or eopardized by the breaking of the glass. In the event, however, it becomes necessary to break the panel 8, or if the sender of the alarm uses an instrument to break the panel,thc same.

may be readily broken and under ordinary conditions the impact will be sufficient to cause an inward swing of the end A of lever 9 to release the latch B and permit the door to swing open; but if for any reason the latch does not open,iaccess can be had through the broken pane or panel to the pull lever or outwardly, as indicated in dotted lic ward edge of the keeper is key, thus rendering the device fool-proof. A new frangible panel 8 may.be' readily insertedin' the rabbet behind the spring D and the arm A of the lever 9, if required.

In Figure 3 a modification of the lever 9.

is shown, in the form of the lever 9 provided with a double or yokelike arm instead of the single arm A. This yoke arm A is designed to have its extremities lie on each side of a panel and engage therewith so as to eliminate any possibility of the panel twisting under the impact of a blow without transmitting the inward movement of the panel to the lever.

A further modification of the invention is shown in Fig. 4 wherein the door to the key or lever guard 4i, has the latch means operated by the inward movement of the door 5 instead of by the inward movement of the glass panel only. In this form of the inven tion the frangible panel 8 may be rigidly mounted in the door, but subject to renewal in the usual manner if broken, and any impact received on the panel 8 or on the frame of the door will cause the door 5 to move inwardly for a slight distance. This movement of the door causes the detent to ride on the bevel surface of the keeper 16 and thereby be depressed a distance to permit the spring pressed pawl 17 to engage in the notch 18, thus releasing the door from closed position and permitting a suitable actuating means, such as shown at 7 in Fig. 2, to move the door to open position as soon as the pressure of the impact has been moved from the door 5 or the panel 8 After the alarm has been given the detent 16 may be released from ineffective position by withdrawing the pawl 17 and the door swung back and snapped to latch position. It will be noted that the forprevent the detent from being depressed sufficiently, while the door is being closed,

to permit the pawl 17 to en age in the notch 18. In this form of the invention as in the form shown in Figs. 1 to 3 inclusive, the frangible panel will be of sufficient thickness to withstand the ordinary blow of the hand, but it may be broken when necessity requires.

It will be manifest that should the guarddoor 5 or 5 become accidentally open it may be snapped in close position by any person.

What I claim is:

1. A key or lever guard for fire alarm boxes incluoing a movable cover member to be positioned before said key or lever and normally biased to move to opened position, means for holding said cover in closed position before said key or lever and for releasing said cover upon pressure against a portion of the cover in a direction opposite to the normal opening movement of the cover.

2. A guard consisting of a movable cover member to be arranged before a key or lever of a fire alarm box, means normally tending normally to open position, the door 1n closed position before said key or lever, said holding means ncluding mechacut away at 19 to when an exterior pressure'is exerted against a portion of said cover in a direction opposite the normal opening movement of the cover. i

3. A. guard to be arranged before a key or lever of a fire alarm box and including a door having a transparent portion therein to expose said key or lever and tending tomove meansfor holding nism for actuating the same to release the door, when external pressure 1s exerted against a portion thereof to move said portion slightly in a direction opposite to the opening movement of the door, whereby the door is allowed to move to open position to expose said key or lever when said pressure is removed.

4. A guard to be arranged before a key or v lever of a fire alarm box and'including a door having a transparent portion therein to expose said key or lever, and, tendingto move normally to open position, means for holding the door in closed position before said key or lever, said holdingmeans including ,inecha- Inisni for actuating thesame to release the door, when external pressure is exerted against the transparent portion thereof, and

allow thedoor to move to'open positionto expose said key or lever, said transparent portion of the door consisting of a frangible element adapted to be broken by an unusual pressure or blow exerted against the transparent portion. f V

5.. A guard forthe key or pull lever of fire alarm boxes consisting of a door pivotally mounted at its lower end and tobe disposed before said key or lever, meansfor 1naintaining said'door in said last mentioned position and for releasing the door when external pressure or a blow is exerted thereagainst,

means for swinging said door open on its pivot when so released, and a movable frangible element insaid door adapted to witha stand ordinary pressure or a blow' from the hand. and ioperatively associated with said dgor releasing means, whereby the latter may be actuated.v w i y 6. A guard for a key or pull lever of fire alarm boxes comprising a door likeelement consisting of a frame mounted to be moved to closed position before said key or lever,

a transparent element'adapted to withstand v ordinaryblows from'the hand and mounted in said frame to have a relative movement thereto under external pressure or a blow thereagainst, means for maintaining said door in normally closed position before said key orlever and actuated by said relative frame and of such character as to withstand pressure or an ordinary blow from the hand, said panel having yieldmgly inward movement relative tothe frame under said pressure or blow, a latch means on the frame for normally holding said. door in closed posi-- tion and arranged relative to said'panel to be actuated by the inward movement of fer to release said door. o

8. In an attachment for signal boxes, an inclosure including a door-likeinember pivoted at its lower edge, means normally urging said door to open position, a frangible transparent panel in said door of such character as to Withstand pressure or a blow, from the hand, spring means for maintaining said panel in position in the door and yieldable under said pressure or blow to permit said panel to have an inward movement relative to thedoor, a latch means normally maintaining' the door in closed position, a portion of said latch means being arranged relative to said panel to be engaged by the latter when moved inwardly relative to the door, whereby the latch'means is actuated to release the door. v V '9. A guard attachment for signal boxes, a door pivotally mounted at its'lo'wer edge, a frangible transparent panel mounted in said door of such character as towithstand pressure or a blow, from the hand, a spring secured to the door and having one-portion engaging a stationary member and an opposite portion engaging said panel, whereby the door is normally urged to swing open and said panel is yieldingly maintained in the door, and a latch means normally maintain ing said door in closed position and having a part thereof positioned to be engaged. by said panel when moved inwardly under pres sure or blow, whereby said latch means is actuated to release said door.

10. A guard attachment for signal boxes, a door pivotally mounted at its lower edge, a frangible transparent aanel of such character as to withstand pressure or a blow, from the hand, mounted in said door to move inward- 'ly under said pressure or blow relative to the door, means normally urging said door to open position, an inwardly extending bracket on said door, a pivoted latch member on the bracket and having two angular arms extending outwardly toward the door, one of said arms being positioned toengage with .theedge of the door opening for maintaining the door in closed position to engage with said panel, whereby the latch member is renthe lat- MICHAEL J. GRACE. 7

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